In my article listing the somatostatin analogues and their drug delivery systems pipeline (click here), there has been a very interesting development in a product called Q-Sphera (was previously known as Q-Octreotide). In a press release, it was announced that an unnamed ‘pharma giant’ has signed a deal with Midatech Pharma Plc that will see it evaluate the latter’s Q-Sphera drug delivery platform. Later in Feb 2019, the pharma was identified as China Medical System Holdings Limited (based out of Hong Kong). Adding to the excitement behind this development, it was announced in Mar 2019 that the Spanish Government had conditionally approved a €6.6m loan that will be used to help commercialise this flagship drug.
Midatech’s Q-Sphera™ is an advanced microencapsulation and polymer-depot sustained release (SR) drug delivery platform produced using a novel and disruptive printing based process, with numerous and distinct advantages over conventional reactor based technologies. From a manufacturing perspective Q-Sphera™ is a precise, scalable, efficient, and environmentally friendly microparticle platform. From a clinical perspective Q-Sphera™ ensures monodispersed microparticles that release active drug compounds into the body in a superior linear tightly controlled and predictable manner over an extended period of time from 1 – 6 months. An injection lasting 6 months sounds very exciting but I have no more detail on the feasibility or likelihood of such a change in frequency with Octreotide or Lanreotide but the press release does mention the possibility, i.e. “Q-Sphera allows drug compounds to be released into the body in a “highly controlled manner” over a prolonged period of time; potentially from a few days to up to six months.”
What’s the main differences?
The current trials are based on the use of Sandostatin LAR (Octreotide) using the Q-Sphera delivery system (previously known as Q-Octreotide). The key aspects of usability are reconstitution and needle size but there is also an inference that less frequent injections could be possible. A comparison of the trial output is as follows:
Reconstitution: For Sandostatin LAR (SLAR)™ the procedure to prepare the product for injection is a complex 30 step error prone process, taking up to 40 minutes and, once reconstituted, the product has to be given immediately to prevent solidifying and wastage of the injection. For MTD201™ Q-Octreotide the preparation process is a simple 5 – 7 minute procedure, after which the product is stable up to 2 hours. For the nurse preparing and giving the injection, the short and flexible process of MTD201™ has clear advantages over the all consuming SLAR process™.
Needle size: For SLAR, a large 19G needle is prescribed for the injection to prevent blockage, and often an even large 18G needle is required for successful injection. For MTD201 Q-Octreotide the precision microencapsulation technology means that a much smaller 21G needle can be used, and there are no blockages. Other Q-Sphera products use even finer needles as small as 27G. The importance of this is evident from the first-in-human phase I data where MTD201 had lower injection pain – 8% for MTD201 versus 25% for SLAR™, and much lower injection site
tenderness – 8% for MTD201 versus 83% for SLAR.
This is an exciting development and I will keep this article live with further information as I receive it.
It’s no secret that Neuroendocrine Cancer can be difficult to diagnose. Although earlier diagnosis is improving (as reported in the SEER database report issued in 2017), there is still a lot of ground to cover. It’s also no secret that certain cancers are difficult to diagnose (NETs is one) and there are a number of reasons why this happens, including but not limited to: – they grow silently, they often produce vague symptoms which can be mistaken for much more common illnesses, and their complexity is not fully understood.
I wanted to cover two different aspects of the problem of finding NETs. Firstly, in finding the primary tumour so that the type of NET can be properly established – this drives the best treatment regime. Secondly in finding all the tumours, as this establishes the correct and most detailed staging declaration – this drives treatment plans and surveillance regimes that need to be put into place.
Hunting Tumours – Primary vs Secondary
It’s really important to determine which tumours are primary and which are secondary (metastasis). There’s a number of ways to help work this out and knowledge of NETs epidemiology studies can help.
Specialist Knowledge – certain things are known about the behaviour of NETs
Specialists and in particular NET specialists will be aware of the vagaries of NETs in terms of what tumours are normally a primary and which are normally secondary and many of the pitfalls involved in working that out. Many NETs will have metastasized to the liver at diagnosis, so whilst it is not impossible to have a primary liver NET, the vast majority of liver tumours found will be secondary (metastases). NET Specialists are more likely to have the experience than generalists. They know that the varying metastatic potential depending on the primary site clearly indicates differing biology and genetics across sites and they know that NETs are indeed a heterogeneous group of tumours. The differences cannot be explained by whether the NET is situated in the foregut, midgut, or hindgut. For example, Appendiceal NET is known to be less prone to metastasis. This may be due to the high rate of incidental findings during appendectomies, or because the appendix is an immunological organ where malignant cells can therefore be expected to be frequently recognized by the immune system.
The majority of the digestive tract is drained by the portal venous system, explaining the dominance of liver metastases in this group of tumours. This also explains our finding that many nervous system and bone metastases originate from NETs in the lungs. Disseminated tumour cells may directly reach the systemic circulation from the lungs, whereas if originating from the midgut region, they need to first pass both the liver and the lungs.
As an example of this heuristic knowledge, one Swedish study indicated that two-thirds of peritoneal metastases will be attributed to Small Intestine NETs (SI NETs). SI NETs and Pancreatic NETs (pNETs) are the most likely to metastasize. The least likely sites to metastasize are the Appendix and Rectum. The same study indicated that in addition to the common metastatic locations of lymph nodes and liver, Lung NETs are more likely to metastasize to the brain and bone than other types. I believe the findings from this study more or less correlates to other information I’ve had access to and also confirms the technical behaviour paragraph above.
Multiple Primary Tumours
With NETs there are two scenarios:
1. Multiple primaries in same organ/location (multicentric). This is fairly common in small intestine (SI NETs), stomach/gastric NETs (gNETs), and also found in Lung and pNETs too. NET experts will be aware of the issue and know to look for the possibility. This is an important point with SI NETs as it’s quite long although held together by the mesentery, so a ‘Mark 1 eyeball’ can be more efficient in finding NETs in this organ than scans. There is a very well known surgical technique called “running the bowel” where they check the small intestine for signs of other primary tumours – they can do the same with the large intestine. Additional surgeries due to this lack of knowledge could come with significant morbidity. Multiple ‘nodes’ and ‘lesions’ are common in the thyroid.
2. Multiple primaries in different locations. This is common with Multiple Endocrine Neoplasia (MEN) syndromes (the name gives it away) and these may be metasynchronous. MEN1 for example can have tumours in what is called the ‘3 P’ locations, pituitary, pancreas and parathyroid. Of course MEN guys may also have multiple primaries in the same organ (multicentric). Read more about MEN by clicking here.
There’s probably a third scenario (for all cancers) and that is multiple primaries with different cancers (i.e a second, third and fourth cancer etc). Synchronous would be really unlucky but metasynchonous is more likely and there are many NET patients with a second cancer.
What else helps find a NET?
There are many other clues open to those involved in diagnosing a NET:
Patient. Very often the patient plays a big part of determining where the primary and other tumours might be by carefully describing symptoms.
Incidental Finds. NETs are very often found incidentally during trips to the ER/A&E and also during tests for something else. This is particularly the case with Appendiceal NETs and might explain why the average age of a patient is significantly lower in this type of NET.
Blood tests and Hormone Markers. We are not yet in a position where these types of tests can diagnose (but we are moving in that direction). In the case of unknown primaries (CUP), sometimes test results can help to find where some of these cancers started. With NETs, symptomatic patients can often test to confirm an elevated hormone marker which may narrow it down to a specific organ or gland. Read more here.
Scans and Endoscopies. Most cancers of a certain size may show up on conventional scanning such as CT, MRI and Ultrasound. Nuclear scans are now playing a bigger part in finding tumours which betray their location through functional behaviour by lighting up or glowing on these imaging devices. Endoscopies (e.g. gastroscopies, colonoscopies, even gastro intestinal pill cameras can be used) can help but like scans are not foolproof). Generally with NETs, if you can see it, you can detect it. Read more here.
Hereditary Conditions. Around 5-10% of NETs are hereditary in nature, mostly involving the MEN group of syndromes. Many of those people will know they are at risk of developing NETs and their doctors should know the most common locations for primary tumours associated with each gene. So a declared or suspected hereditary syndrome is useful in finding primary tumours if they exist and are proving difficult to find.
Biopsies. “Tissue is the issue”. Pathology can very often give really strong clues as to the type of NET and therefore the likely location of a primary tumour, for example additional tests such as immunostains. Many biopsies will come from secondary cancer (metastases), mostly the liver. Despite all the potential diagnostic routes above, the place the cancer started is sometimes still not found and this may lead to atypical diagnostic/treatment plans and in certain cases this might even include exploratory biopsies via surgery (invasive/minimally invasive), perhaps combined with opportunistic tumour removal if found during the procedure.
Staging. Simple staging can be given if locations of metastases are known. For example in the case of Liver metastases, the stage is automatically Stage 4. However, the full staging definition relies on knowing distant metastases, loco-regional metastases and the full Tumour/Node/Metastases (TNM) definition (size, spread, etc) cannot be fully complete without a primary. Read more here.
Cancers of Unknown Primary
Cancer is always named for the place where it started, called the primary site. Sometimes doctors can’t tell where a cancer may have started. When cancer is found in one or more places where it seems to have spread, but the site where it started is not known, it is called a cancer of unknown primary (CUP) or an occult primary cancer.
When you look at the ratio of all cancers, the figure for cancers of unknown primary (CUP) is quite startling. Depending on where you look the figure is around 2-10%. That doesn’t seem a lot but when you consider the amount of people diagnosed with cancer, the total figure must be staggering. Interestingly, Cancer Research UK say that 60% of CUP cases are in the over 75s. In another interesting Swedish study, doctors claimed that the rates of metastatic cases were higher with certain NETs than they were in their anatomical counterparts, reinforcing the dangerous and sneaky nature of NETs.
Despite quite advanced scanning and diagnostic testing currently in place, and the extensive knowledge of NET specialists, there can still be reasons for not being able to find the primary tumour:
The primary is just too small to be seen and is growing quite slow. Very small cancers might not cause symptoms or be seen on scans. This is a particularly relevant point with NETs.
The primary could be hidden in tissue in between different organs causing confusion about the actual primary location.
The body’s immune system killed the primary cancer. It’s also possible (but not common) that any secondary cancer (i.e. metastases) is still growing.
The tumour has become loose from its primary location and exited the body, e.g. from a wall of the bowel and excreted out in the stool.
The primary cancer was removed during surgery for another condition and doctors didn’t know cancer had formed. For example, a uterus with cancer may be removed during a hysterectomy to treat a serious infection.
Summary
I hope this is useful for many NET patients, particularly those who are looking for a diagnosis or looking for a primary tumour.
Neuroendocrine Cancer – at times, it can really be like looking for a needle in a haystack.
This is a ‘next generation’ Peptide receptor radionuclide therapy (PRRT) or more specifically the radiopharmaceutical that binds to both activated and unactivated somatostatin receptors which are upregulated on these tumours. There is far higher binding via this mechanism than standard octreotate. The technical name of the radiopharmaceutical is Satoreotide tetraxetan lutetium-177 (author’s note, I’m guessing but it could be a variant of Lanreotide). It was once named JR11.
What’s the difference to the current approved therapy?
Conventional PRRT (e.g. Lutathera, Lu177 Dotatate) is based on a somatostatin receptor ‘agonist’ approach, whereas 177Lu Ops 201 Satoreotide is a receptor ‘Antagonist’. The differences are quite technical but in the most layman terms , the antagonist has the capability of attaching (binding) to more receptors, including those in a ‘resting’ or ‘inactive’ state, spends more time on the tumor than agonist based therapies. The result is a higher number of receptor binding sites and greater tumor uptake. In addition it is said to show an improved tumor-to-kidney dose ratio compared to 177Lu-DOTA-TATE.
This would also be reflected in the theranostic use of the drug in Ga68 imaging (i.e. Ga68 Satoreotide).
The clinical trial is named “Study to Evaluate the Safety and Preliminary Efficacy of 177Lu-OPSC001 in NETs”. The protocol involves 3 cycles 8 weeks apart of intravenous Lu-177 OPS-201. All patients will have baseline Ga-68 octreotate imaging performed.
The treatment is available for all NET patients with a histologically confirmed diagnosis of:
unresectable GEP NET (Grade I and Grade II according to WHO classification (2010, Annex 01), functioning and non-functioning).
unresectable “typical lung NET” or “atypical lung NET” are acceptable (with the exception of Large Cell Bronchial Neuroendocrine Neoplasms and Small Cell Lung Cancers).
malignant, unresectable pheochromocytoma or paraganglioma
Patients who have previously had Lu-177 octreotate (e.g. Lutathera) are not eligible. Patients may have had any other treatment including chemotherapy, radiotherapy or Somatostatin Analogues (e.g. octreotide, landreotide).
There are other inclusion and exclusion criteria to be found within the clinical trial document. The trial is due to compete in May 2022.
Where is the Trial based?
At the time of writing and according to the Clinical Trial document, Australia (Melbourne and Perth), Austria (Vienna), Denmark (Aarhus), Switzerland (Basel), UK (Royal Free London). Two sites are also listed in France (Nantes and Toulouse) but trial document currently marked as not yet recruiting.
I have anecdotal evidence to suggest one more UK site is possible in 2019, Windsor in UK, a private healthcare provider but it will be open to public and private patients.
What about USA?
I also found an additional trial based in Memorial Sloan Kettering New York designed to take a theranostic approach by using Satoreotide (JR11) for the pre-treatment imaging, e.g. Ga68 satoreotide (JR11) and the 177Lu version for treatment. The clinical trial document indicates this trial is active but NOT RECRUITING and is entitled “Theranostics of Radiolabeled Somatostatin Antagonists 68Ga-DOTA-JR11 and 177Lu-DOTA-JR11 in Patients With Neuroendocrine Tumors”
Thanks for reading
You may also find these PRRT related articles useful:
In my article listing the somatostatin analogues and their drug delivery systems pipeline (click here), there has been a very interesting development in a product called Q-Sphera (was previously known as Q-Octreotide). In a press release, it was announced that an unnamed ‘pharma giant’ has signed a deal with Midatech Pharma Plc that will see it evaluate the latter’s Q-Sphera drug delivery platform. Later in Feb 2019, the pharma was identified as China Medical System Holdings Limited (based out of Hong Kong). Adding to the excitement behind this development, it was announced in Mar 2019 that the Spanish Government had conditionally approved a €6.6m loan that will be used to help commercialise this flagship drug.
